The invention relates to a safety device for a vehicle door handle, in particular in order to avoid unsolicited opening of said door during a side crash scenario.
When a vehicle undergoes a lateral collision, the inertia of the handle pieces can lead to an actuation of the door latch. Major risk in that case is the opening of the door, meaning that the occupants are directly exposed to the outside, while free objects can be thrown out of the vehicle.
It is known to use movement prevention devices, actuated by the important accelerations often of several tens of g that lock the handle to avoid opening of the vehicle door. Most commonly, said movement prevention devices use an inertial mass which is moved by inertia so as to enter a blocking position. In said blocking position, blocking means engage with the latch or handle mechanics in a way that prevents opening of the door.
The known movement prevention devices can be divided in two main categories: temporary blocking and permanent blocking. The temporary blocking devices use returning means such as a spring to bring back the inertial mass in a non-blocking position as soon as the acceleration diminishes beyond a predetermined value. The permanent blocking devices have no means to bring back the inertial mass in the non-blocking position, and often comprise in addition means to keep the blocking means engaged with the latch or handle mechanics even after the crash subsequent accelerations are gone.
The temporary blocking devices ensure that a rescuer or anyone wishing to activate the door handle can open the door from outside once the vehicle has stabilized itself for pulling the occupants of the vehicle out. The problem with said temporary blocking devices is that vibrations and the inertia oscillations due to rebounds of the vehicle or to secondary impacts are likely to free the blocking means of the movement blocking device from the handle mechanism.
Permanent blocking devices are more effective in keeping the door closed during the crash, but the latches or handles remain blocked in locked state even when the doors could be opened safely again.
Damped inertial systems use a temporary blocking architecture, in which a rotational damper selectively delays the return to the non-blocking position of the movement prevention device. Movement prevention devices using damped inertial systems combine the advantages of both permanent and temporary blocking devices. During the crash, the movement prevention device is maintained in blocking position during the risk time interval, and returns to non-blocking position afterwards, allowing easy evacuation of the vehicle.
The inertial systems must conform to specific requirements and scope statements, that may differ from one country to another. Also, the involved door handle pieces may vary from one vehicle model to another, in particular the mobile part of the handle and its weight. Consequently, various models of inertial systems have to be developed and distributed, tuned specifically for a particular door handle model.
This lack of uniformity leads to additional expenses in that the inertial systems cannot be produced in very high numbers, which reduces the individual price of the individual inertial systems. This also increases the logistic complexity, as the different inertial systems must be delivered to the different production sites of each corresponding vehicle type.